Exhaust Washer Mods

[jlee]

Gotta be no cats, damn the numbers from emissions testing equipment, right? 2 stroke motor vs 4 stroke has nothing to do with that at all....

 

[Gillbot]

Catalytic convertors exist for a reason. You might be making little CO and NOx under certain conditions but not all. Pollution its a lot more important than amount of fuel burned. There is a reason a scooter pollutes 10x as much as a car... no cats

But overall, the more fuel burned the more "pollution" produced regardless.

 

[AdamK47]

I think you should do it.

 

[JCH13]

Doing it right would be before the cat not after.

So the 'right' way dumps fumes out where you can inhale them and you can get all that fun nitric and sulfuric acid all over the underside of your car? Suuure.

 

[Gillbot]

So the 'right' way dumps fumes out where you can inhale them and you can get all that fun nitric and sulfuric acid all over the underside of your car? Suuure.

Not when you are driving. Maybe when you are sitting which you shouldn't be for long periods anyway.

 

[WilliamM2]

So the 'right' way dumps fumes out where you can inhale them and you can get all that fun nitric and sulfuric acid all over the underside of your car? Suuure.

I see a flange there, and no cutoff valve. I would think that would be piped further downstream, so fumes shouldn't be an issue.

 

[Throckmorton]

But overall, the more fuel burned the more "pollution" produced regardless.

No. A cat reduces mpg slightly but reduces pollution by orders orders of magnitude

 

[Gillbot]

No. A cat reduces mpg slightly but reduces pollution by orders orders of magnitude

And cats or not, all things being equal, a car with cats that burns more fuel still produces more pollution than a car with cats that burns less fuel.

 

[Kadarin]

2. You do it far enough back (right before the muffler) that you still have enough backpressure from the rest of the piping.

Jumping into this thread to comment on this part... I really don't understand why this myth continues to persist. Backpressure is resistance to the piston rising on the exhaust stroke, and it is NEVER beneficial in any way, shape, or form.

Backpressure does not build low-end torque. If you believe that it does, I'd be really interested in hearing you describe the physics behind how it does.

This myth stems from the fact that gas will flow through narrower pipes with a higher velocity, and that higher velocity will promote improved torque at low rpm by scavenging the exhaust gas out of the cylinder. However, at higher rpm the narrower pipe cannot flow as much total volume as a wider pipe, and thus backpressure builds.

If you were to increase backpressure by shoving a potato in your exhaust pipe, you will gain no torque whatsoever.

 

[JCH13]

I see a flange there, and no cutoff valve. I would think that would be piped further downstream, so fumes shouldn't be an issue.

I'd like to think so too... but you never know. Heh.

Not when you are driving. Maybe when you are sitting which you shouldn't be for long periods anyway.

Do you know where the cabin air inlet is? Or any firewall vents? I can smell exhaust, coolant, and PCV/oil vapor leaks in my Miata through the firewall vents and hvac system, it's worse with the hardtop on and windows up.

 

[Throckmorton]

And cats or not, all things being equal, a car with cats that burns more fuel still produces more pollution than a car with cats that burns less fuel.

Yes and modding a car in such a way that it burns 5% more fuel is much better than modding it in such a way that it produces 20x as much air pollution.

But many power adding mods increase gas mileage. For example a 93 octane tune on a 4.6L Mustang improves gas mileage because less energy is wasted by having the retarded spark timing required for 87 octane. Same goes for things that decrease restriction like exhaust and intake mods.

 

[Gillbot]

Do you know where the cabin air inlet is? Or any firewall vents? I can smell exhaust, coolant, and PCV/oil vapor leaks in my Miata through the firewall vents and hvac system, it's worse with the hardtop on and windows up.

Depends on the model of car, but it's the general blanket statements thrown about that make me laugh at threads like this.

Yes and modding a car in such a way that it burns 5% more fuel is much better than modding it in such a way that it produces 20x as much air pollution.

But many power adding mods increase gas mileage. For example a 93 octane tune on a 4.6L Mustang improves gas mileage because less energy is wasted by having the retarded spark timing required for 87 octane. Same goes for things that decrease restriction like exhaust and intake mods.

Ok, you win. From now on, all I need are cats and I can put absolutely any mod on a car without harming the environment. Thanks!

 

[Throckmorton]

Depends on the model of car, but it's the general blanket statements thrown about that make me laugh at threads like this.


Ok, you win. From now on, all I need are cats and I can put absolutely any mod on a car without harming the environment. Thanks!

Wow, so you really don't understand the difference between burning slightly more fuel or even slightly less, and releasing 10x as much pollutants that directly cause health problems and smog?

You're like the idiots promoting scooters at the Earth Day festival in Dallas. I told him my ULEV Mustang pollutes far less

 

[jlee]

Yes and modding a car in such a way that it burns 5% more fuel is much better than modding it in such a way that it produces 20x as much air pollution.

You're making me want to go get my emissions test done sans cat just so I can show you how far off your numbers are.

 

[Gillbot]

Wow, so you really don't understand the difference between burning slightly more fuel or even slightly less, and releasing 10x as much pollutants that directly cause health problems and smog?

You're like the idiots promoting scooters at the Earth Day festival in Dallas. I told him my ULEV Mustang pollutes far less

No I do understand the difference, I just don't agree with your random numbers and lack of evidence. Nor do I really care to discuss it anymore because you will always be right in your own mind so there is no point. Let me ask you this though, you are telling me that a 2000HP car with a cat will produce less pollution than a 200HP car without one?

You're making me want to go get my emissions test done sans cat just so I can show you how far off your numbers are.

THIS ^

They put my Camaro on the OBDII test and it passed with flying colors NO CAT. They didn't believe it should have so they put it on the sniffer and it passed. I guess it doesn't matter since it pollutes 20x more without a cat regardless.....

My old Festiva passed the sniffer test without a cat as well. It had a carburetor but it ran like a top, though, there is no way since it polluted 20x more without a cat on it. :rollseyes:

 

[shabby]

So the 'right' way dumps fumes out where you can inhale them and you can get all that fun nitric and sulfuric acid all over the underside of your car? Suuure.

I made sure to point the 90 degree elbow down not up into the cabin.

 

[Throckmorton]

No I do understand the difference, I just don't agree with your random numbers and lack of evidence. Nor do I really care to discuss it anymore because you will always be right in your own mind so there is no point. Let me ask you this though, you are telling me that a 2000HP car with a cat will produce less pollution than a 200HP car without one?



THIS ^

They put my Camaro on the OBDII test and it passed with flying colors NO CAT. They didn't believe it should have so they put it on the sniffer and it passed. I guess it doesn't matter since it pollutes 20x more without a cat regardless.....

My old Festiva passed the sniffer test without a cat as well. It had a carburetor but it ran like a top, though, there is no way since it polluted 20x more without a cat on it. :rollseyes:

Oh so cats exist for no reason? They do nothing? It's all just a big conspiracy right? Cities were not more polluted back before the regulations started requiring them? The MAN is lying when HE tells you that a lawnmower pollutes 20x as much as a car?

Or could it be that the careful tuning to achieve such low emissions of the gases they test for in your locality, under a very particular set of circumstances, is irrelevant in the real world?


I'm not sure if this has occurred to you, but a 2000hp engine and a 200hp engine are both producing about the same 30hp to keep a car rolling along at cruise speed. So they are burning about the same amount of fuel, aside from differences in efficiency.

 

[JCH13]

Depends on the model of car, but it's the general blanket statements thrown about that make me laugh at threads like this.

Okay, fair enough, it might not be a problem for every single car.

How about this: it is very bad practice to vent exhaust ahead of the cabin.

 

[Gillbot]

Oh so cats exist for no reason? They do nothing? It's all just a big conspiracy right? Cities were not more polluted back before the regulations started requiring them? The MAN is lying when HE tells you that a lawnmower pollutes 20x as much as a car?

Or could it be that the careful tuning to achieve such low emissions of the gases they test for in your locality, under a very particular set of circumstances, is irrelevant in the real world?


I'm not sure if this has occurred to you, but a 2000hp engine and a 200hp engine are both producing about the same 30hp to keep a car rolling along at cruise speed. So they are burning about the same amount of fuel, aside from differences in efficiency.

As I said, I care not to discuss it further because you are arguing semantics. What people do to modify their car CAN AND WILL affect emissions. The cats are there to cover up the idiots who don't maintain, tune or mod their cars properly.

Also, I would be willing to wager against anyone that said 2000hp car uses WAY more than 30hp every time it rolls out. Someone doesn't build a 2000hp car to baby it like a 200hp one not to mention flogging the shit out of a 200hp car will still likely produce less than someone toying around in a 2000hp car. The right foot will control emissions and we can agree that if the power is there, at some point it WILL get used otherwise we'd all be driving a prius.

 

[Ferzerp]

This thread makes me weep for humanity.

 

[LTC8K6]

http://www.myfoxny.com/story/22936908/cops-mom-kids-overcome-by-fumes-in-car-with-faulty-exhaust

http://news.ninemsn.com.au/national/2013/06/08/13/22/exhaust-fumes-link-to-baby-sa-crash-death

There's still plenty enough CO in a modern car's exhaust to kill you quickly via an exhaust leak.

In these cases, the tail pipe was blocked, but I bet if the exhaust system was tight like it should be, the engine would stall.

http://www.examiner.com/article/bos...f-carbon-monoxide-poisoning-while-sitting-car

http://carbonmonoxide-poisoning.com...carbon-monoxide-deaths-of-three-in-maine.html

 

[JulesMaximus]

Reactions are catalyzed. I don't think it's proper to say a substance has been 'catalyzed.' It has been converted to another substance by a chemical reaction.

That bit of nit-picking aside, I don't think harmful gases like CO are at a high enough level in modern cars to make an under-car exhaust leak a serious concern.

You would probably need a combination of poor running condition and a way for exhaust to enter the cabin (unsealed hole around a manual shifter seems like a common one)...the kinds of things that kids that would do a 'washer mod' probably have, actually...

If you want your exhaust to be louder, get a muffler that...muffles less. Or replace one or more mufflers with a piece of pipe. It's not that hard/expensive. I still might hate you for it, but I'd wouldn't laugh at you quite so much. Spacing pipe connections apart with washers might as well be drilling random 'speed holes' in your exhaust.

:thumbsup::biggrin: I'm going to market that and start selling 'Speed Holes' on ebay.

 

[TridenT]

And cats or not, all things being equal, a car with cats that burns more fuel still produces more pollution than a car with cats that burns less fuel.

Incorrect.

Most motorcycles use less fuel than most cars and have no cats. Yet, in California, they make up 1% of miles driven and 10% of the smog.

 

[LTC8K6]

Yep, motorcycles are some gross polluters, despite burning a lot less fuel.

 

[jlee]

Incorrect.

Most motorcycles use less fuel than most cars and have no cats. Yet, in California, they make up 1% of miles driven and 10% of the smog.

I thought you were talking about cars. Now we're comparing motorcycle emissions to car emissions?